The invention relates to a stator for an electric motor, in particular for an external rotor motor, comprising a basic body with a laminated stator core as well as stator coils arranged on the laminated stator core, each having a winding wire start and a winding wire end, wherein each winding wire start is connected to contact pins, while the basic body is extrusion coated with a sleeve made from plastic, from which the contact pins at least partially protrude.
The so-called spray-molding technique is frequently used in order to protect the coil of electric motors against environmental influences. A completely wound stator coil is encased herein with a duroplastic or thermoplastic molding compound by means of a spraying process. As a result of the mechanical properties, this molding compound can also assume other functions. In order to make possible at the same time a simple and cost-effective assembly, for example, by means of a modular design, the electrical connections must be lead to the outside. This is frequently carried out by means of contact plugs.
In designs that correspond to the state of the art, the winding wires are positioned at the same time primarily manually in contact elements, which were previously secured on the stator by means of a pressing process. An auxiliary element must furthermore be positioned on the stator in order to ensure the necessary guide and protection of the winding wires for the spray-molding process, and the auxiliary element fulfills this function. The actual contact of the winding wires takes place then by means of hot pressing.
The tool that forms the hollow space for spray-molding during the spray-molding technique must incorporate recesses for these contact plugs, which are greater than the contact elements. In the known technical solutions used in the practice, material penetrates disadvantageously into the hollow spaces formed by the recesses and the contact pins during spray-molding. It must therefore frequently be manually removed in a separate downstream procedure.